ABSTRACT Aim: Venous thromboembolic event (VTE) is a common complication for cancer patients, leading to hospitalizations that increase the burden of cancer management. We evaluated the incidence and costs of VTE-related hospitalizations for patients with breast cancer (BC) or prostate cancer (PC), two of the most frequent cancers in France. Methods: We used the French national hospital database (PMSI) to select new patients with BC or PC in 2010, who had at least one VTE-related hospitalization during the following two years. VTE-related stays and patients were identified using the disease-specific ICD-10 codes. Hospital costs were estimated from the healthcare system perspective and included care, treatments, accommodation/investment costs and medical/technical procedures, using the French official tariffs. Results: Among 107,916 new patients with BC or PC, 2,268 were hospitalized for a VTE, representing an overall of 2,814 admissions. VTE was classified as primary or related diagnosis (PD/RD) in 1,004 (36%) admissions. Among those PD/RD admissions, pulmonary embolism was the most frequent diagnosis as it led to 626 (62%) stays. Deep venous thrombosis was the second cause of hospitalization (248 admissions; 25% of PD/RD admissions). Re-hospitalisation for recurrence was frequent, as it occurred 546 cases (19.4%) of all VTE-related hospitalizations. For a patient who did not experience recurrence, the mean cost per patient was e3,302 and e3,611 for BC and PC patients respectively. But this annual amount was highly increased for patients with recurrent VTE, to e5,545 per BC patient and e5,692 per PC patient. Finally, VTE-related hospitalizations were responsible for an overall expenditure of e3.40 million over two years, including e335,000 due to recurrent events. Table: Mean annual VTE-related hospitalization cost per patient. With one VTE only With recurrent VTE Annual cost per breast cancer patient e3,302 e5,545 Annual cost per prostate cancer patient e3,611 e5,692 Conclusions: In cancer patients, VTE-related hospitalizations remain frequent and induce an elevated cost. Adequate prophylaxis and management could be an efficient way to reduce the incidence of this common complication and its economic burden. Disclosure: F. Scotte, I. Borget and N. Martelli: I have honoraria from Leo Pharma. All other authors have declared no conflicts of interest.